Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:108941
MIME-Version: 1.0
References: <CAEPJdunSr8PkBtSLO8g_JMLzM4cFVnXsQSEMFmu2RN25XT=grw@mail.gmail.com>
 <2227A758-3035-4A43-974C-C4461A096DFB@newclarity.net> <CALKiJKqD=rZLN9r999byR=bDVhjiKLJ1ODKqZbwmfY9AojooSg@mail.gmail.com>
In-Reply-To: <CALKiJKqD=rZLN9r999byR=bDVhjiKLJ1ODKqZbwmfY9AojooSg@mail.gmail.com>
Date: Tue, 10 Mar 2020 11:36:59 +0000
Message-ID: <CALKiJKqQJFQaZp91DLy2bb9tWgwtoAfkWZq9yHpqY+sDeNkvDA@mail.gmail.com>
To: PHP Internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="00000000000056147f05a07e8a63"
Subject: Re: [PHP-DEV] [RFC] Attributes v2
From: rowan.collins@gmail.com (Rowan Tommins)

--00000000000056147f05a07e8a63
Content-Type: text/plain; charset="UTF-8"

On Tue, 10 Mar 2020 at 10:54, Rowan Tommins <rowan.collins@gmail.com> wrote:

>
> C#: [Foo]
> Rust: #![Foo] or #[Foo]
> C++: [[Foo]]
> Java: @Foo
> ECMAScript (proposed): @Foo
> Go: `Foo` or "Foo"
> Doctrine et al: /** @Foo */
> Hack: <<Foo>>
>
>

To add to that list, Python decorators, which serve a similar purpose, also
use @Foo, and in confirming that I came upon some interesting discussions
of how they came to that syntax in https://www.python.org/dev/peps/pep-0318/
and a long list of alternative proposals at
https://wiki.python.org/moin/PythonDecorators


There was apparently an alternative proposal for a "using" keyword, but it
was ultimately rejected in favour of the punctuation form. Not all of the
considerations apply to the PHP case, but this quote from Guido is rather
interesting:


> The keyword starting the line that heads a block draws a lot of attention
to it.
> This is true for "if", "while", "for", "try", "def" and "class". But the
"using" keyword (or any other keyword in its place)
> doesn't deserve that attention; the emphasis should be on the decorator
or decorators inside the suite,
> since those are the important modifiers to the function definition that
follows.
> When a function definition carries one or more decorators, the most
important information
> is not the fact that it has decorators, but the specific decorators used.


I think that applies to our case equally: any punctuation or keyword is
just a separator between the main function declaration and the specific
attribute being applied. Having to write "attribute Sealed" would be like
having to write "visibility public"; as much as possible, we want "Sealed"
to be the keyword, and the rest of the syntax to just be formatting.


Regards,
-- 
Rowan Tommins
[IMSoP]

--00000000000056147f05a07e8a63--